Large size tiled display device

ABSTRACT

A large size tiled display device includes a plurality of display panels having an image display part including a plurality of pixels. Each pixel includes at least three sub-pixels. A frame has a plurality of panel receiving portions to receive the plurality of display panels. The frame has an outer wall frame and a partition wall frame, each of which has a vertical surface and an inclined surface extending from the vertical surface that tapers the frame. A light guide plate is formed of a cluster of optical fibers. The light guide plate is disposed on the display panels to reproduce an image formed on the image display part of the display panels. Each optical fiber corresponds to one sub-pixel.

RELATED APPLICATIONS

The present patent document is a divisional of U.S. patent applicationSer. No. 11/152,953, filed Jun. 14, 2005, which claims priority toKorean Patent Application No. 46694/2004 filed in Korea on Jun. 22,2004, which is hereby incorporated by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to a large size display device, andparticularly, to a large size tiled display device capable of preventinga seam phenomenon and improving light transmittance efficiency.

2. Description of the Related Art

In general, the importance of an electronic display device is increasingas a visual information transmitting device and the electronic displaydevice enlarges the scope of industry with the implementation of aninformation society. Diversification of information, represented by term‘multimedia’, makes the usefulness of the electronic display deviceclearer. Simultaneously, the demand for an electronic display devicehaving a large screen, providing a high quality image and goodvisibility and being economical is also increasing. Particularly, it isdesirable for portable information devices to have low powerconsumption.

A liquid crystal display (LCD) device is one of the electronic displaydevices and is thin, light and consumes low power. Because of suchcharacteristics, the LCD device has an increasing application market,and the demand thereof is rapidly increasing because of color display.Also, as the standard of living of consumers is improved, a producthaving a bigger size and better image quality is demanded. Therefore,faculties for establishing technologies to mass-produce a color liquidcrystal display device with a large screen are desired.

The color LCD device with a large screen has a limit in a screen size,and a maximum panel size which has been known so far is 22 inches, andit is known that 40-inch panel may be produced theoretically.

Thus, what is called a projection TV having an optical system with asmall panel to form a large image on a screen has emerged. However,despite such development, a limit in implementing a large screen stillexists. For this reason, a tiled liquid crystal display device in whichseveral liquid crystal panels are tiled to form a large size displaydevice is being put to practical use.

FIG. 1 is a structural view which illustrates a tiled LCD device.

As shown, the tiled LCD device 10 is formed by fixing a plurality ofliquid crystal panels 30 a˜30 d on a frame 20. Here, each of the liquidcrystal panels 30 a˜30 d may form one unit as a backlight assembly, aliquid crystal plate, a liquid crystal layer and polarization membersare attached thereto. The frame 20 includes an outer wall frame 20 aforming an outer wall, a partition wall frame 20 b interposed betweenpanels and a bottom plate 20 c which the panels 30 a˜30 d are put on.Here, each of the panels 30 a˜30 d is received in a space formed by thepartition wall frame 20 b and the outer wall frame 20 a and is tiled.

In a method of constructing a large screen using the tiling technology,because an image is not formed at the partition wall frame 20 b, a seamphenomenon occurs in that a boundary line is displayed on the screencorresponding to the partition wall frame 20 b. Thus, anentirely-unified image cannot be displayed.

BRIEF SUMMARY

By way of introduction only, in one aspect, a tiled display devicecomprises a plurality of display panels having an image display partincluding a plurality of pixels. Each pixel includes at least threesub-pixels. A frame has a plurality of panel receiving portions toreceive the plurality of display panels. A light guide plate comprisesoptical fibers. The light guide plate is disposed on the display panelsto reproduce an image formed on the image display part of the displaypanels. Each optical fiber corresponds to one sub-pixel.

In another aspect, a tiled display device comprises a plurality ofdisplay panels having an image display part including a plurality ofpixels. Each pixel includes four sub-pixels of the same area. A framehas a plurality of panel receiving portions to receive the plurality ofdisplay panels. A light guide plate comprises optical fibers. The lightguide plate is disposed on the display panels to reproduce an imageformed on the image display part of the display panels. Each opticalfiber corresponds to one pixel.

In another aspect, a tiled display device comprises a plurality ofdisplay panels having an image display part including a plurality ofpixels. Each pixel includes a plurality of sub-pixels. A frame has aplurality of panel receiving portions to receive the plurality ofdisplay panels. The frame has an outer wall frame and a partition wallframe. An inner side of the outer wall frame includes a vertical surfaceformed to a certain height and an inclined surface extending outwardfrom the vertical surface. The partition wall frame has verticalsurfaces formed at both sides to the certain height and inclinedsurfaces extending inward from the vertical surfaces. A plurality oflight guide plates is mounted in the panel receiving portions.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described herein,there is provided a large size tiled display device comprising: aplurality of display panels having an image display part including aplurality of pixels, each pixel including first˜fourth sub-pixels; aframe having a plurality of panel receiving portions to receive theplurality of display panels; and a light guide plate formed of a clusterof optical fibers and disposed on the display panels to reproduce animage formed on the image display part of the display panels, oneoptical fiber corresponding to one pixel, wherein the four sub-pixelsdefining the pixel have the same area.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute aunit of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a structural view which illustrates a related tiled LCDdevice;

FIG. 2 is a structural view which illustrates a large size tiled displaydevice in accordance with the present invention;

FIG. 3 is a structural view which illustrates a liquid crystal panel;

FIG. 4 is a sectional view taken along line I-I′ of FIG. 2;

FIG. 5 is a view which illustrates a light guide plate;

FIG. 6 is a plan view which illustrates a tiled display device inaccordance with the present invention;

FIG. 7 is a plan view which illustrates the tiled display device inaccordance with another embodiment of the present invention;

FIG. 8 is a plan view which illustrates the tiled display device inaccordance with still another embodiment of the present invention; and

FIG. 9 is a plan view which illustrates the tiled display device inaccordance with still another embodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERREDEMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

FIG. 2 is a schematic exploded perspective view which illustrates atiled display device in accordance with the present invention, FIG. 3 isa view which illustrates a display panel (liquid crystal panel) indetail, and FIG. 4 is a sectional view taken along line I-I′ of FIG. 2.

As shown in FIG. 2, the tiled display device 100 is formed by fixing toa frame 120, a plurality of display panels 130 a˜130 d and light guideplates 140 a˜140 d respectively formed on the display panels 130 a˜130d. Here, as the display panel 130 a˜130 d, a liquid crystal displaypanel (LCD), a field emission display panel (FED), a plasma displaypanel (PDP), an electroluminescence (EL) or the like may be used.

Particularly, as shown in FIG. 3, if the display panels 130 a˜130 d areliquid crystal panels, each of the display panel 130 includes a firstsubstrate 131, a second substrate 135 and a liquid crystal layer 138formed between the first and second substrates 131 and 135.

The first substrate 131, a thin film transistor array substrate,includes gate lines 133 and data lines 132 that define a plurality ofpixel regions. A switching device (not shown) for switching each pixelis formed at each of regions where the gate lines and the data lines 132intersect each other, and a pixel electrode 134 for driving a liquidcrystal is formed at the pixel region.

The second substrate 135, a color filter substrate, includes a colorfilter layer 136 for implementing actual colors and a black matrix 139for preventing light leakage between the pixels. Here, the color filterlayer 136 is formed such that red, green and blue (R, G and B) colorfilters are disposed in regions corresponding to the pixel regions,respectively. Also, a common electrode 137 for driving the liquidcrystal together with the pixel electrode 134 is formed on the colorfilter layer 136.

Here, although not shown in the drawing, the common electrode 137 andthe pixel electrode 134 may be formed on the same plane (e.g., on thefirst substrate). If the common electrode 137 and the pixel electrode134 are formed on the same substrate, a viewing angle may be improved byhorizontal driving of the liquid crystal.

Referring to FIG. 2 again, as for the tiled display device in accordancewith the present invention, the frame 120 includes an outer wall frame120 a forming an outer wall, a partition wall frame 120 b interposedbetween panels and a bottom plate 120 c which the panels 130 a˜130 d andthe light guide plates 140 a˜140 d can be put on. Here, each of thedisplay panels 130 a˜130 d is received in a space formed by thepartition wall frame 120 b and the outer wall frame 120 a and is tiled.

As shown in FIG. 4, an inner side of the outer wall frame 120 a includesa vertical surface 121 a formed to a certain height and an inclinedsurface 121 b upwardly extending from the vertical surface 121 a. Theinclined surface 121 b is formed inclined such that a thickness of theouter wall frame 120 a gets narrower in an upward direction, thevertical surface 121 a corresponds to a side portion of the displaypanel 130 c, 130 d, and the inclined surface 121 b corresponds to aninclined surface formed at a side portion of the light guide plate 140c, 140 d. Also, vertical surfaces 122 a are formed at both sides of thepartition wall frame 120 b to a certain height, and inclined surfaces122 b upwardly extend from the vertical surfaces 122 a. Here, each ofthe inclined surfaces 122 b is inclined such that the partition wallframe 120 b gets narrower in an upward direction.

Also, inclined surfaces are formed at side portions of the light guideplates 140 c and 140 d, to meet the inclined surfaces 121 b and 122 b ofthe partition wall frame 120 b and the outer wall frame 120 a. Here, theinclined surfaces of the light guide plates 140 c and 140 d are inclinedcorresponding to the inclined surfaces of the frames.

As shown in FIG. 5, the light guide plate 140 is formed of a cluster ofoptical fibers 141. The optical fibers 141 are distributed over anentire upper surface of the display panel 130 such that one set of endsform a lower surface of the light guide plate 140 and the opposing setof ends form an upper surface of the light guide plate 140. Here,because the upper surface of the light guide plate 140 has a larger areathan that of the lower surface, the optical fibers 141 are inclined froma center portion toward an outer edge of the light guide plate 140.Accordingly, a seam phenomenon which occurs at a boundary surfacebetween related display panels is prevented. Namely, in comparison withthe related art, an image is displayed through the optical fibers evenat the boundary surface between the display panels, namely, at thepartition wall frame region, such that an image can be reproducedcontinuously.

A diameter of an optical fiber 141 which is being commonly manufacturedis within a range of 500˜1000 μm. In case of a liquid crystal panel,lengths of a short side and a long side of a pixel defined by a gateline and a data line are about 100 μm and 200 μm, respectively, eventhough there are variations according to model. Also, because a sectionof the optical fiber has a circular shape, an image displayed throughthe light guide plate 140 has lower brightness than that of an imagedisplayed at an actual display panel.

This will now be described in more detail with reference to theaccompanying drawing. FIG. 6 is a front view of the light guide plate.As shown, the light guide plate 140 is formed as a cluster of opticalfibers 141, and a diameter of the optical fiber 141 has a size enough tocover at least two pixels. Also, a BM (black matrix) film 150 isattached on the light guide plate, and the shape of the BM is formed asa regular hexagonal shape with regard to an aspect of good visibility.

Because the optical fiber 141 has a circular shape, the light guideplate 140 cannot be completely filled with optical fibers 141 and thus,a dead region (D) is generated between the optical fibers 141. Becausethe optical fiber 141 reproduces an image formed on a display panel, animage of a display panel 130′ corresponding to the dead region (D)cannot be reproduced by the light guide plate 140.

To solve such problems, the present invention provides a tiled displaydevice that can improve light transmittance efficiency as a pixeloccupying the optical fiber is formed as large as possible (with themaximum area) and thus the dead region D is minimized.

FIG. 7 is a tiled display device in accordance with the presentinvention devised to improve the light transmittance efficiency.Although not shown in the drawing, a structure of a frame for receivingthe display panel and the light guide plate is the same as that of theprevious embodiment (FIG. 4).

As shown, as for the tiled display device 200 in accordance with thepresent embodiment, sub-pixels 260 a, 260 b and 260 c are designed suchthat one optical fiber 241 corresponds to one sub-pixel. Namely, theoptical fibers 241 are matched one to one with the sub-pixels 260 a, 260b and 260 c, and the optical fibers 241 are respectively disposed at theR (red), G (green) and B (blue) sub-pixels 260 a, 260 b and 260 c. Here,each of the sub-pixels 260 a, 260 b and 260 c is formed to occupy thecorresponding optical fiber 241 as large as possible (with the maximumarea). In other words, because the optical fiber 241 has a circularshape, the sub-pixel 260 a, 260 b and 260 c may also have a circularshape identical to the optical fiber 241. In general, because a diameterof the optical fiber 241 is within a range of 500˜1000 μm, a size of asub-pixel 260 a, 260 b and 260 c varies according to the optical fiber241 used.

Also, a BM film 250 having a BM pattern of a regular hexagonal shape maybe attached to each boundary region between the optical fibers 241(i.e., a region corresponding to a boundary region between sub-pixels)thereby improving a CR (contrast ratio). Here, the sub-pixels 260 a, 260b and 260 c may have a regular hexagonal shape identical to the BMpattern.

As for the case that the sub-pixels 260 a, 260 c and 260 c are designedas a regular hexagonal shape, as shown, the optical fibers 241 arerespectively disposed within the sub-pixels 260 a, 260 b and 260 c.Here, a dead region (D′) in which the optical fibers cannot cover thesub-pixels 260 a, 260 b and 260 c is generated because the optical fiber241 has a circular shape. However, the dead region (D′) is remarkablysmall compared to that in the previous embodiment (refer to FIG. 6).Therefore, light transmittance efficiency may be improved.

Also, because an arrangement of the R, G and B sub-pixels 260 a, 260 band 260 c is identical to an arrangement of the optical fibers 241.

As shown in FIG. 8, a sub-pixel 260 d such as W (white), Y (yellow), M(magenta) or the like may be additionally formed to improve brightnessof a display panel 230′. Here, one pixel includes R, G, B and W or Y orM 260 a, 260 b, 260 c and 260 d.

Also, to implement a high-brightness tiled display device, the foursub-pixels including the W, Y or M sub-pixel may correspond to oneoptical fiber in the present invention.

FIG. 9 shows a high-brightness tiled display device in which one pixel360 is disposed at one optical fiber 341 in a display panel where foursub-pixels define one pixel.

As shown, in the high-brightness tiled display device 300 in accordancewith the present embodiment, one pixel 360 is disposed in one opticalfiber 341. The pixel 360 includes first˜fourth sub-pixels 360 a˜360 d.The first˜third substrates 360 a˜360 c are R, G and B sub-pixels, andthe fourth sub-pixel 360 d may be W, Y or M sub-pixel.

Only, the first˜fourth sub-pixels 360 a to 360 d are designed to havethe same area within the optical fiber 341. Here, the pixel 360including the first˜fourth sub-pixels 360 a˜360 d may be designed as aregular hexagonal shape identical to a shape of a BM pattern or as acircular shape identical to a shape of the optical fiber 341.

Also, any shape of the first˜fourth sub-pixels is allowable if they havethe same area within the optical fiber 341.

As described so far, the present invention can prevent a seam phenomenonoccurring at a boundary surface between display panels by installinglight guide plates on the display panels. Particularly, in the presentinvention, the light guide plate is formed of a cluster of opticalfibers, and R, G and B sub-pixels defining one pixel are respectivelydisposed in optical fibers, thereby improving light transmittanceefficiency.

Also, in the present invention, as for a high-brightness tiled displaydevice in which W, Y or M sub-pixel is added, one unit pixel defined bya plurality of sub-pixels (e.g., four sub-pixels) may be disposed at oneoptical fiber. Here, if the four sub-pixels defining the pixel have thesame area within the optical fiber, any shape of the sub-pixels may beallowable.

As described so far, the present invention may provide a large sizedisplay device that provides high image quality thanks to the improvedlight efficiency because a seam phenomenon is prevented by using a lightguide plate formed of optical fibers and a pixel is designed so as tominimize a dead region generated between the optical fibers.

As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the metes and bounds of theclaims, or equivalence of such metes and bounds are therefore intendedto be embraced by the appended claims.

1. A large size tiled display device comprising: a plurality of displaypanels having an image display part including a plurality of pixels,each pixel including first˜to fourth sub-pixels; a frame having aplurality of panel receiving portions to receive the plurality ofdisplay panels; a light guide plate formed of a cluster of opticalfibers and disposed on the display panels to reproduce an image formedon the image display part of the display panels, one optical fibercorresponding to one pixel; and a black matrix (BM) film including a BMof a regular hexagonal shape, the BM being formed at a boundary betweenthe optical fibers corresponding to the pixels, wherein the foursub-pixels having the same area.
 2. The device of claim 1, furthercomprising: a black matrix (BM) film including a BM of a regularhexagonal shape, the BM being formed at a boundary between the opticalfibers corresponding to the pixels.
 3. The device of claim 1, whereinthe first sub-pixel is a red (R) sub-pixel, the second sub-pixel is agreen (G) sub-pixel, the third sub-pixel is a blue (B) sub-pixel, andthe fourth sub-pixel is a white (W) sub-pixel.
 4. The device of claim 1,wherein the first sub-pixel being a red (R) sub-pixel, the secondsub-pixel being a green (G) sub-pixel, the third sub-pixel being a blue(B) sub-pixel, and the fourth sub-pixel being a yellow (Y) sub-pixel. 5.The device of claim 1, wherein the first sub-pixel being a red (R)sub-pixel, the second sub-pixel being a green (G) sub-pixel, the thirdsub-pixel being a blue (B) sub-pixel, and the fourth sub-pixel being amagenta (M) sub-pixel.
 6. The device of claim 1, wherein the framehaving an outer wall frame and a partition wall frame, an inner side ofthe outer wall frame including a vertical surface formed to a certainheight and an inclined surface extending outward from the verticalsurface, the partition wall frame having vertical surfaces formed atboth sides to the certain height and inclined surfaces extending inwardfrom the vertical surfaces.